I didn't think our Montana HC did too bad in some cold weather we encountered in September (well below freezing overnight, didn't get above 40 with no sun and super windy outside during the day, in WY). We utilized the fireplace as a space heater, and kept the heat around 62 and just wore an extra layer. But, I think part of the problem is, people expect it to be like their house in the winter. No trailer right off the lot is that well insulated. If I were stationary and living in it full time, I would spend the money on some good skirting.